We demonstrate a high-sensitivity ultrafast emission spectrometer based on the optical Kerr effect that time resolves emission simultaneously in the ultraviolet and visible ranges. We show that using benzene as the Kerr medium leads to the optimal balance between time-resolution and sensitivity of the optical shutter with low losses due to ultraviolet absorption. Using this medium together with high contrast broadband polarizers and charge-coupled device detection, we achieve efficient detection of emission transients (bandwidth >1.5 eV) in a time bin of ∼500 fs. To highlight the distinctive insights that can be gained by resolving complex subpicosecond dynamics in a single experiment, we present UV-visible transient emission spectra of technologically relevant wide bandgap zinc oxide. With an enhanced broadband detection, subpicosecond effects such as thermalization, bandgap renormalization, and carrier trapping can be easily assessed, with ramifications for optoelectronics and energy-related technologies.

A multimode interference filter with narrow transmission bandwidth and large self-imaging wavelength interval is constructed and implemented in an ytterbium doped fiber laser in all-fiber format for broad wavelength tunability as well as narrow spectral width of the output beam. The peak transmission wavelength of the multimode interference filter was tuned with the help of a standard in-fiber polarization controller. With this simple mechanism more than 30 nm (1038 nm–1070 nm) tuning range is demonstrated. The spectral width of the output beam from the laser was measured to be 0.05 nm.

In this Note, it is pointed out that emissive probes cannot be used to directly and reliably measureplasma potential fluctuations. An experimentally validated model demonstrates indeed that the floating potential fluctuations of an emissive probe which floats at the mean plasma potential depend not only on the plasma potential fluctuations but also on electron density and temperaturefluctuations.

In multi-pass Thomson scattering (TS) scheme, a laser pulse makes multiple round trips through the plasma, and the effective laser energy is enhanced, and we can increase the signal-to-noise ratio as a result. We have developed a coaxial optical cavity in which a laser pulse is confined, and we performed TS measurements using the coaxial cavity in tokamakplasmas for the first time. In the optical cavity, the laser energy attenuation was approximately 30% in each round trip, and we achieved a photon number gain of about 3 compared with that obtained in the first round trip. In addition, the temperature measurement accuracy was improved by accumulating the first three round trip waveforms.

Force curves recorded with the atomic force microscope on structured samples often show an irregular force versus indentation behavior. An analysis of such curves using standard contact models (e.g., the Sneddon model) would generate inaccurate Young's moduli. A critical inspection of the force curve shape is therefore necessary for estimating the reliability of the generated Young's modulus. We used a trained artificial neural network to automatically recognize curves of “good” and of “bad” quality. This is especially useful for improving the analysis of force maps that consist of a large number of force curves.

The free-surface Liquid-Lithium Target, recently developed at Soreq Applied Research Accelerator Facility (SARAF), was successfully used with a 1.9 MeV, 1.2 mA (2.3 kW) continuous-wave proton beam. Neutrons (∼2 × 1010 n/s having a peak energy of ∼27 keV) from the 7Li(p,n)7Be reaction were detected with a fission-chamber detector and by gold activation targets positioned in the forward direction. The setup is being used for nuclear astrophysics experiments to study neutron-induced reactions at stellar energies and to demonstrate the feasibility of accelerator-based boron neutron capture therapy.

This paper proposes a novel piezoelectrically driven pipette, which utilizes centrifugal force in swing motion of a vibrating tube as the driving force, to input and output liquid at first bendingresonant frequency. Control circuit capable of frequency tracking is designed. Pulse volume changing with different driving voltage amplitude, driving frequency, tip size, and target reagents are studied in experiments. The output pulse volume of a prototype pipette driven by voltage of 560 Vpp at 175.9 Hz is 43.2 μl with a variation of ±3.5%. Minimum water spots of 3 μl can be deposited in this manner. This pipette represents an alternative to standard liquid transfer techniques in chemical or biological experiments.

We present a real-time absolute air refractometer benefiting from the synthetic pseudo-wavelength (SPW) method. Based on laser heterodyne interferometry, the SPW method uses three vacuum cells with specific lengths to synthesize a set of synthetic pseudo-wavelengths, by combination of which the refractive index can be determined directly without ambiguity. In addition, owing to the parallel arrangement of the vacuum cells in the optical path, the measured data can be collected simultaneously so that one measurement process can be less than 2 ms. The real-time feature makes it possible for instantaneous compensation for laser interferometers.

We present a completely practical TunaDrive piezo motor. It consists of a central piezo stack sandwiched by two arm piezo stacks and two leg piezo stacks, respectively, which is then sandwiched and spring-clamped by a pair of parallel polished sapphire rods. It works by alternatively fast expanding and contracting the arm/leg stacks while slowly expanding/contracting the central stack simultaneously. The key point is that sufficiently fast expanding and contracting a limb stack can make its two sliding friction forces well cancel, resulting in the total sliding friction force is <10% of the total static friction force, which can help increase output force greatly. The piezo motor's high compactness, precision, and output force make it perfect in building a high-quality harsh-condition (vibration resistant) atomic resolution scanning probe microscope.

A Raman detection platform integrated with both fluorescence and dark field microscopes was built for in situ Raman detection with the assistance of fluorescence and dark field imaging to locate the target micro regions. Cells and organelles can be easily found via fluorescenceimaging with labeling techniques. Besides, nano-sized particles could be observed and located by dark field microscopes. Therefore, comparing with the commercial Raman spectrometers, much more researches based on Raman spectroscopy could be carried out on this integrated Raman platform, especially in the fields of analyzing biological tissues and subwavelength samples.